Method of Manufacturing Raschel Lace Knitted Fabric

ABSTRACT

A method of manufacturing a Raschel lace knitted fabric. In a knitting step, a Raschel knitted fabric is knitted by inserting an insertion yarn made of the same type of material as a first chain stitch yarn into a chain stitch weave which is knitted by feeding the first chain stitch yarn made of a meltable material and a second chain stitch yarn having a higher melting temperature than the first chain stitch yarn from different beams to individual reeds. Heat treatment is performed for a treatment time in which the second chain stitch yarns and a weft passage yarn remain as yarns, at a temperature equal to or lower than the melting temperature of the second chain stitch yarn and equal to or higher than the melting temperature of the meltable material, in a state where the Raschel knitted fabric is stretched.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2017-85520 filed Apr. 24, 2017, the disclosure of which is hereby incorporated in its entirety by reference.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a Raschel lace knitted fabric, which obtains the Raschel lace knitted fabric by executing a knitting step of knitting a Raschel knitted fabric by feeding a plurality of chain stitch yarns each forming a chain stitch weave extending in a knitting direction, a weft passage yarn which is knitted in a knitted fabric weft direction between a plurality of chain stitch weaves formed by the chain stitch yarns, and a thermal melting yarn exhibiting weldability by being partially or entirely melted by being heated, to a Raschel knitting machine, and a heat treatment step of heat-treating the Raschel knitted fabric which is obtained through the knitting step.

BACKGROUND

A method of manufacturing a Raschel lace knitted fabric which is difficult to be frayed, by executing such a knitting step and a heat treatment step of heat-treating a Raschel knitted fabric which is obtained through the knitting step, is disclosed in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4. In the techniques disclosed in the former three patent documents, a so-called covering yarn is used. In contrast, in the technique disclosed in Patent Document 4, a chain stitch weave itself is knitted from two yarns.

In the technique disclosed in Patent Document 1, the covering yarn is knitted into a scallop portion.

The covering yarn is composed of a core yarn having thermal meltability and a cover yarn (also referred to as a sheath yarn) which is a thermoplastic synthetic fiber yarn, and after knitting, a lace knitted fabric is heated, whereby a part of the core yarn is melted, a melted material exudes from between the cover yarns, and the melted material is bonded to another yarn adjacent thereto and solidified. As a result, in a knitted lace product, fraying in the scallop portion can be prevented.

Patent Document 2 is to obtain a Raschel stretch lace by using a covering yarn for a chain stitch yarn itself in order to eliminate inconsistency in aesthetic appearance and a feel in the scallop portion and the other portions in the technique disclosed in Patent Document 1.

In Patent Document 3, a lace knitted fabric 120 after knitting is heated to a temperature lower than the melting temperature of a chain stitch yarns 21 and equal to or higher than the melting temperature of an insertion yarns 23, whereby a part of the insertion yarn 23 which is a covering yarn is partially melted (in Patent Document 3, this melting is referred to as dissolution). A part of the melted portion sticks to the chain stitch yarn 21 and a weft passage yarn 22. Accordingly, the connected state of each of the yarns 21 to 23 is maintained, and thus fraying of the yarn is prevented. Further, a welded portion 100 is formed by fracturing the insertion yarn 23. Therefore, even if a part of the chain stitch yarns 21 configuring a chain stitch weave is cut off, raveling of the chain stitch weave is blocked by the sticking portion of the insertion yarn 23, and thus it is considered that it is possible to suppress raveling of the chain stitch weave beyond the sticking portion.

In the technique disclosed in Patent Document 4, as described previously, each of the chain stitch weaves is composed of two yarns, in which one of the two yarns is a low melting point yarn, and the low melting point yarns are bonded to each other at a contact portion between the yarns in a state of forming the chain stitch weave. As the low melting point yarn, nylon (specifically, nylon 6, nylon 66, or nylon 12) is adopted, and this yarn is a yarn which does not substantially have stretchability,

RELATED ART DOCUMENT Patent Document

[Patent Document 1] JP-A-H11-081073

[Patent Document 2] JP-A-2008-280627

[Patent Document 3] JP-A-2009-013554

[Patent Document 4] JP-A-S63-152444

SUMMARY Problem that the Invention is to Solve

As described above, development for obtaining a product which is excellent in terms of aesthetic appearance and a feel while solving a fraying problem, as a Raschel lace knitted fabric, has been continued for a long time. However, in the technique disclosed in Patent Document 2 mentioned above, the covering yarn is used for the chain stitch yarn, and therefore, skill is required for knitting and a yield cannot be earned.

Further, the core yarn of the covering yarn is a melting yarn, and therefore, it is necessary to expose the core yarn from between the cover yarns (the sheath yarns), and thus it is difficult to control tension during heat treatment.

Therefore, the technique of using the covering yarn for the chain stitch yarn itself has not been practically used in practice.

On the other hand, in the technique disclosed in Patent Document 3, a yarn having a relatively high melting point, such as nylon, is adopted for the chain stitch yarn, a relatively thin polyester-based thermoplastic polyurethane elastic yarn is inserted, as the insertion yarn, into the chain stitch weave which is formed by the chain stitch yarn, and the subsequent heat treatment step is executed.

In Patent Document 3, it is described that in this way, it is possible to obtain a knitted lace (the Raschel lace knitted fabric in the present invention) in which it is possible to prevent fraying of a yarn. However, according to the study by the inventors of the present invention, bonding between the chain stitch yarn and the thermal welding yarn which configure the chain stitch weave did not occur sufficiently, and thus there was room for improvement.

In the technique disclosed in Patent Document 4, as described previously, the low melting point yarns which are yarns on one side of the yarns configuring the chain stitch weave are welded to each other at a contact portion where they come into contact with each other, and therefore, the knitted fabric itself becomes very rigid and is not practical. Further, nylon is adopted as the low melting point yarn, and therefore, from this point as well, the knitted fabric becomes hard and stretchability cannot be imparted to the knitted fabric.

In view of the above circumstances, a main object of the present invention is to provide a method of manufacturing a Raschel lace knitted fabric, in which it is possible to effectively solve a fraying problem and it is possible to obtain a knitted fabric having stretchability.

Means for Solving the Problem

According to a first aspect of the present invention, there is provided a method of manufacturing a Raschel lace knitted fabric, which obtains the Raschel lace knitted fabric by executing

a knitting step of knitting a Raschel knitted fabric by feeding a plurality of chain stitch yarns each forming a chain stitch weave extending in a knitting direction, a weft passage yarn which is knitted in a knitted fabric weft direction between a plurality of chain stitch weaves formed by the chain stitch yarns, and a thermal melting yarn exhibiting weldability by being partially or entirely melted by being heated, to a Raschel knitting machine, and

a heat treatment step of heat-treating the Raschel knitted fabric which is obtained through the knitting step,

in which in the knitting step,

a plurality of chain stitch weaves are knitted in which a meltable yarn portion made of thermally weldable polyurethane which is a meltable material which is partially or entirely melted by being heated is set to be a first chain stitch portion, a poorly-meltable yarn portion made of a poorly-meltable material having a higher melting temperature than the meltable material is set to be a second chain stitch portion, the first chain stitch portion and the second chain stitch portion are provided in the same chain stitch weave, and a surface of the first chain stitch portion is in an exposed state, and

a Raschel knitted fabric is knitted in which the weft passage yarn is set to be a poorly-meltable yarn made of a poorly-meltable material having a higher melting temperature than the meltable material, and an insertion yarn made of a polyurethane material is inserted into the chain stitch weave, and

in the heat treatment step,

heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than melting temperatures of the poorly-meltable material and the weft passage yarn and equal to or higher than a melting temperature of the meltable material in a knitted fabric tensioned state where a contact portion between the first chain stitch portion and the insertion yarn is formed is executed for a treatment time in which each of the poorly-meltable yarn portion, the weft passage yarn, and the insertion yarn remains as a yarn, so that a Raschel lace knitted fabric in which the insertion yarn is welded to the chain stitch weave is obtained.

According to this configuration, in knitting the Raschel knitted fabric, a single chain stitch weave is knitted to be provided with both the first chain stitch portion and the second chain stitch portion. In this knitting, the insertion yarn made of the same type of material as the meltable material forming the first chain stitch portion is inserted into the chain stitch weave. Specifically, the material of the first chain stitch portion is set to be thermally weldable polyurethane, and the material of the insertion yarn is set to be polyurethane. Further, the first chain stitch portion is used with the surface thereof exposed. By advancing the knitting in this manner, in a form in which the first chain stitch portion and the second chain stitch portion configure the same chain stitch weave, a close portion between the first chain stitch portion and the insertion yarn is formed at a loop portion thereof.

In this way, a Raschel knitted fabric (a raw fabric) is obtained in the knitting step, and the Raschel knitted fabric is heat-treated in the heat treatment step. The heat treatment is performed for a treatment time in which the poorly-meltable yarn portion and the weft passage yarn remain as yarns, at a temperature equal to or lower than the melting temperatures of the poorly-meltable material and the weft passage yarn and equal to or higher than the melting temperature of the meltable material. Further, in this heat treatment, the Raschel knitted fabric is in a tensioned state where tension is applied thereto. In this tensioned state, the close portion between the first chain stitch portion and the insertion yarn becomes a contact portion.

If the heat treatment is performed in this state, in a form in which the poorly-meltable yarn portion and the weft passage yarn which configure a basic structure of a lace knitted fabric remain as yarns retaining the knitted fabric form, the first chain stitch portion configuring the chain stitch weave and the insertion yarn which is inserted into the chain stitch weave are composed of the same type of material and are in contact with each other at the contact portion in the tensioned state, and therefore, the first chain stitch portion and the insertion yarn are reliably melted and welded to each other. Further, a welded portion between the insertion yarn and the second chain stitch portion or the weft passage yarn is also formed. Further, polyurethane is used as the material configuring each of the first chain stitch portion and the insertion yarn, and therefore, stretchability can be imparted to the knitted fabric.

As a result, it is possible to effectively solve a fraying problem, and it is possible to obtain a Raschel lace knitted fabric having sufficient stretchability.

In a method of manufacturing a Raschel lace knitted fabric according to a second aspect of the present invention, a first chain stitch yarn which is made of the meltable material and is a filament yarn and a second chain stitch yarn made of the poorly-meltable material are fed from different beams to individual reeds, and the first chain stitch portion and the second chain stitch portion are knitted in the same chain stitch weave by the first chain stitch yarn and the second chain stitch yarn, respectively, and

the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch yarn and the second chain stitch yarn, so that a Raschel knitted fabric is knitted, and

in the heat treatment step,

heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than the melting temperatures of the second chain stitch yarn and the weft passage yarn and equal to or higher than the melting temperature of the first chain stitch yarn is executed for a treatment time in which each of the second chain stitch yarn, the weft passage yarn, and the insertion yarn remains as a yarn, thereby obtaining a Raschel lace knitted fabric.

According to this configuration, in knitting the Raschel knitted fabric, a single chain stitch weave is knitted with both the first chain stitch yarn which is a filament yarn and the second chain stitch yarn made of a poorly-meltable material. Here, the first chain stitch yarn is set to be a filament yarn, whereby it becomes possible to easily perform knitting. In this configuration, the insertion yarn is inserted into the chain stitch weave. By advancing the knitting in this way, in a form in which the first chain stitch yarn and the second chain stitch yarn configure the same chain stitch weave, a contact portion between the first chain stitch yarn and the insertion yarn is formed at a loop portion thereof.

The reason for using the individual reeds for the first chain stitch yarn and the second chain stitch yarn in the knitting of the knitted fabric is for favorably advancing knitting by independently performing the feeding of each yarn in a yarn feeding state of being suitable for each yarn, because these yarns have different physical properties.

In this way, a Raschel knitted fabric (a raw fabric) is obtained in the knitting step, and the Raschel knitted fabric is heat-treated in the heat treatment step. The heat treatment is performed at a temperature equal to or lower than the melting temperatures of the second chain stitch yarn and the weft passage yarn and equal to or higher than the melting temperature of the first chain stitch yarn. However, the treatment time is set to be a treatment time in which the second chain stitch yarn and the weft passage yarn remain as yarns. By executing such heat treatment, it is possible to make the first chain stitch yarn and the insertion yarn be in a state of being favorably welded to each other at the contact portion, in a form in which the second chain stitch yarn and the weft passage yarn which configure the basic structure of the lace knitted fabric remain as yarns retaining the knitted fabric form.

Further, a structure is obtained in which the insertion yarn, the second chain stitch yarn, and the weft passage yarn are welded to each other.

In a method of manufacturing a Raschel lace knitted fabric according to a third aspect of the present invention, the first chain stitch yarn is a yarn that is thinner than the insertion yarn, a surface of the insertion yarn is melted in the heat treatment in the heat treatment step, and the first chain stitch yarn is welded to the surface of the insertion yarn.

According to this configuration, the melting of the first chain stitch yarn is advanced, and the first chain stitch yarn can be favorably welded to the insertion yarn.

In a method of manufacturing a Raschel lace knitted fabric according to a fourth aspect of the present invention, the first chain stitch yarn is thinner than the insertion yarn.

According to this configuration, by using a polyurethane yarn made of the same material as the first chain stitch yarn and the insertion yarn, welding of both yarns can be assured. According to the verification by the inventor, if heat treatment is performed in a tensioned state (a so-called taut state without sagging) where tension is applied to two polyurethane yarns in a form in which the two polyurethane yarns are in contact with each other at a contact portion, both the yarns are weld to each other on at least the surfaces thereof. By performing heat treatment in the tensioned state in this manner, the fraying problem can be solved at the welded portion. Further, the polyurethane yarn has elasticity, and therefore, it is possible to obtain a so-called stretch lace in which a Raschel lace knitted fabric has elasticity.

In a method of manufacturing a Raschel lace knitted fabric according to a fifth aspect of the present invention, a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine.

In the present invention, the second chain stitch yarn is a yarn which remains in the Raschel lace knitted fabric even after the heat treatment step, and is a relatively thick and highly visually recognizable yarn. On the other hand, the first chain stitch yarn is relatively thin and poor in visibility, because the functional purpose thereof is welding.

Even in such a situation, according to this configuration, the first reed is made to be on the machine front side with respect to the second reed, and therefore, for example, even if trouble such as cutting of the first chain stitch yarn which is relatively thin and poor in visibility occurs during knitting, a worker can easily perform the treatment of the first chain stitch yarn from the front of the Raschel knitting machine.

In a method of manufacturing a Raschel lace knitted fabric according to a sixth aspect of the present invention, the second chain stitch yarn is a nylon yarn.

According to this configuration, a thermally weldable polyurethane yarn is used as the first chain stitch yarn, whereby the welding of this yarn can be assured. As a result, a fraying problem can be solved. Further, a nylon yarn is used for the second chain stitch yarn, whereby the Raschel lace knitted fabric can exhibit a beautiful aesthetic feeling of a lace pattern with a waist and can be made durable.

In a method of manufacturing a Raschel lace knitted fabric according to a seventh aspect of the present invention, a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.

According to this configuration, a yarn feeding amount adjustment mechanism is provided in each of the yarn feeding parts of the first chain stitch yarn and the second chain stitch yarn, and by adjusting yarn feeding tension by adjusting a yarn feeding amount, it is possible to favorably knit the chain stitch weave composed of both the yarns by feeding the yarns having different physical properties to different reeds, respectively.

In a method of manufacturing a Raschel lace knitted fabric according to an eighth aspect of the present invention, the first chain stitch yarn is a thermally weldable polyurethane yarn having a thickness in a range of 17 to 156 dtex and a melting temperature in a range of 150° C. to 180° C., the second chain stitch yarn is a nylon yarn having a thickness in a range of 33 to 78 dtex and a melting temperature of 200° C., the insertion yarn is a polyurethane yarn having a thickness in a range of 156 to 310 dtex and a melting temperature in a range of 190° C. to 220° C., and in the heat treatment step, the Raschel knitted fabric obtained through the knitting step is heat-treated for a time in a range of 30 to 90 seconds at a temperature within a heating temperature range of 190° C. or more and 200° C. or less.

According to this configuration, a portion in which the first chain stitch yarn is welded to the insertion yarn can be reliably formed by knitting a Raschel knitted fabric by using the first chain stitch yarn, the second chain stitch yarn, and the insertion yarn, and performing appropriate heat treatment on the obtained Raschel knitted fabric. Further, by allowing the insertion yarn to remain in the heat treatment, it is possible to obtain a Raschel lace knitted fabric having stretchability.

In a method of manufacturing a Raschel lace knitted fabric according to a ninth aspect of the present invention, in the knitting step, a conjugate yarn having the meltable yarn portion and the poorly-meltable yarn portion in a single yarn is fed to a single reed to be knitted into a chain stitch weave having the first chain stitch portion and the second chain stitch portion, and the insertion yarn is inserted into the chain stitch weave, thereby knitting the Raschel knitted fabric.

According to this configuration, in knitting the Raschel knitted fabric, a chain stitch weave is knitted using the conjugate yarn as a chain stitch yarn. The conjugate yarn which is used here is a yarn in which a single yarn is configured to be provided with both a meltable yarn portion and a poorly-meltable yarn portion, and the meltable yarn portion is melted by the heat treatment which is executed in the heat treatment step, and exhibits weldability. Incidentally, as described above, since the insertion yarn is inserted into the chain stitch weave, the first chain stitch portion of the conjugate yarn comes into contact with the insertion yarn at a loop portion of the chain stitch weave.

As a result, if a Raschel knitted fabric (a raw fabric) is obtained in the knitting step in this way and the Raschel knitted fabric is heat-treated in the heat treatment step, the first chain stitch portion and the insertion yarn of the chain stitch weave enter a state of being favorably welded to each other at the contact portion thereof, in a form in which the poorly-meltable yarn portion and the weft passage yarn which configure the basic structure of the lace knitted fabric remain as yarns retaining the knitted fabric form.

As a result, it is possible to obtain a Raschel lace knitted fabric in which it is possible to effectively solve a fraying problem.

In this manner, in a case of using the conjugate yarn, in the knitting of a knitted fabric, it is sufficient if only one reed is used, and thus it is possible to easily perform the knitting.

In a method of manufacturing a Raschel lace knitted fabric according to a tenth aspect of the present invention, in the knitting step, a chain stitch weave having the first chain stitch portion, the second chain stitch portion, and the insertion yarn is knitted to be provided on the entire Raschel knitted fabric.

In this configuration, it is possible to obtain a Raschel lace knitted fabric in which it is difficult for a fraying problem to occur on the entire knitted fabric.

In a method of manufacturing a Raschel lace knitted fabric according to an eleventh aspect of the present invention, in the knitting step, a yarn different from the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch portion and the second chain stitch portion, as a floating insertion yarn in a knitted form in which a part of the yarn floats on a back surface of the Raschel knitted fabric.

According to this configuration, by inserting the floating insertion yarn, it is possible to obtain a Raschel lace knitted fabric having a good feel as a structure in which this yarn floats on the surface on one side of the Raschel knitted fabric.

As this type of floating insertion yarn, a cotton yarn, a rayon yarn, a polyester multifilament yarn, or the like is preferable.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a weave diagram showing a part of a chain stitch weave of a Raschel knitted fabric which is an embodiment of the present invention;

FIG. 2 is a knitting weave diagram showing a knitted form of the chain stitch weave and an insertion yarn which is inserted into the chain stitch weave;

FIG. 3 is a side view showing a configuration of a Raschel knitting machine capable of independently feeding two chain stitch yarns according to the present invention;

FIG. 4 is a view showing a knitting part of the Raschel knitting machine shown in FIG. 3;

FIGS. 5A to 5E are schematic sectional views for describing movements of a knitting needle and a ground reed of a chain stitch portion;

FIGS. 6A to 6C are schematic sectional views for describing movements of a jacquard bar and a reed for an insertion yarn (reed for thermal bonding);

FIGS. 7A and 7B are operation diagrams showing movement forms of the chain stitch yarn and the insertion yarn relative to the knitting needle for forming the knitting weave shown in FIG. 2;

FIG. 8 is a manufacturing process diagram for manufacturing a Raschel lace knitted fabric; and

FIG. 9 is a weave diagram showing a part of a chain stitch weave of a Raschel knitted fabric of another embodiment.

DESCRIPTION OF EMBODIMENTS

The present invention relates to a method of manufacturing a Raschel lace knitted fabric, and a manufacturing process thereof includes, as main steps, a knitting step s1 and a heat treatment step s2 of heat-treating a Raschel knitted fabric 20 obtained through the knitting step s1, as shown in FIG. 8. The heat treatment step s2 is a step which is also referred to as a heat setting step. After both the steps s1 and s2 are performed, a dyeing step s3 of dyeing a Raschel lace knitted fabric and a resin treatment and drying step s4 of performing resin treatment are executed, and in a cutting and sewing step s5, cutting and sewing are performed so as to satisfy the required use, whereby a product can be obtained. An example of the product is woman's clothing.

A feature of the embodiment described below is that in the knitting step s1, the Raschel knitted fabric 20 is knitted by using a unique Raschel knitting machine 200 which is now improved by the inventors of the present invention and the Raschel knitted fabric 20 is subjected to at least heat treatment.

FIG. 1 shows one of a number of chain stitch weaves 19 configuring the Raschel knitted fabric 20 in this embodiment and shows a knitted state of main yarns (a first chain stitch yarn 21 a, a second chain stitch yarn 21 b, a weft passage yarn 22, and an insertion yarn 23) configuring the chain stitch weave 19. As will be shown later, in the actual Raschel knitted fabric 20, as the weft passage yarn 22, a very large number of yarns are knitted. However, only two of the yarns are shown in FIG. 1.

FIG. 2 is a diagram showing the relationship between a chain stitch yarn 21 configuring such a knitted fabric weave and the insertion yarn 23 forming a pair with the chain stitch yarn 21 in the present invention. In the knitting of the Raschel knitted fabric 20 according to the present invention, the first chain stitch yarn 21 a and the second chain stitch yarn 21 b form the chain stitch weave 19 with the same operation, and therefore, in this drawing, one of them is omitted (the same in FIG. 7A). In FIG. 2, other yarns except for the chain stitch yarn 21 configuring the chain stitch weave 19 and the insertion yarn 23 which is inserted into the chain stitch weave 19 are also omitted.

FIGS. 7A and 7B show the positional relationships between the respective yarns (the chain stitch yarn 21 and the insertion yarn 23) and a knitting needle 72 in a knitting operation, in a case of knitting the Raschel knitted fabric 20 having this chain stitch weave. In the drawings, a lateral arrow corresponds to the movement of a reed (in the case of FIG. 7A, a ground reed 65, and in the case of FIG. 7B, a reed for an insertion yarn 61) with respect to each needle 72.

In FIG. 2, the respective chain stitch weaves 19 are knitted weaves that are independent of each other. However, in fact, a large number of weft passage yarns 22 (refer to FIG. 1) are knitted between the chain stitch weaves 19, so that the Raschel knitted fabric 20 is formed.

Referring to FIG. 1, a feature of the Raschel knitted fabric 20 which is knitted through the knitting step s1 is that the chain stitch yarn 21 which forms the chain stitch weave 19 is composed of two types of yarns 21 a and 21 b and the insertion yarn 23 is inserted along a knitting direction C (a knitted fabric warp direction) into the chain stitch weave 19 formed in this way.

In the Raschel knitted fabric 20, one yarn 21 a of the chain stitch yarn 21 is set to be a thermal melting yarn made of a thermally meltable material. The thermal melting yarn 21 a is also referred to as a thermal welding yarn. The yarn 21 a has thermoplasticity and is melted by being heated to a temperature equal to or higher than a predetermined temperature to be welded to the insertion yarn 23 which is made of the same material as the thermal melting yarn 21 a and is in contact with the thermal melting yarn 21 a.

The other yarn 21 b of the chain stitch yarn 21 is set to be a yarn made of a poorly-meltable material having a higher melting temperature than the meltable material.

Therefore, in this embodiment, the first chain stitch yarn 21 a becomes a first chain stitch yarn portion made of a meltable material, and the second chain stitch yarn 21 b becomes a second chain stitch yarn portion made of a poorly-meltable material.

In this embodiment, the two types of yarns 21 a and 21 b are independent yarns, and therefore, the surface of the thermal melting yarn 21 a (the first chain stitch yarn portion) is naturally exposed.

In FIG. 1, only one chain stitch weave 19 is shown. However, in this embodiment, all the chain stitch weaves 19 (all wales) forming the Raschel knitted fabric 20 have the above configuration. As a result, in the heat treatment step s2, the thermal melting yarn 21 a configuring a part of the chain stitch weave 19 is welded to at least the insertion yarn 23, so that a Raschel lace product in which fraying does not occur regardless of a portion at which the Raschel lace knitted fabric is cut and a way of cutting the Raschel lace knitted fabric can be obtained.

Here, almost the entirety of the thermal melting yarn 21 a is melted by the heat treatment. According to the confirmation by the inventors, in the Raschel lace knitted fabric according to the present invention, a portion Y at which the thermal melting yarn 21 a was welded to the insertion yarn 23 was effective in prevention of fraying. That is, even if the knitted fabric was expanded and contracted, the effect to prevent fraying was not lost.

The overview of the invention is as described above.

Hereinafter, 1. Knitted fabric weave, 2. Yarn use, 3. Raschel knitting machine, 4. Manufacture of Raschel lace knitted fabric will be described in this order.

1. Knitted Fabric Weave

As shown in FIG. 1, the Raschel knitted fabric 20 according to the present invention is configured to be provided with the plurality of chain stitch yarns 21 a and 21 b each configuring the chain stitch weave 19 extending in the knitting direction C, the weft passage yarn 22 which is knitted in a knitted fabric weft direction W between the chain stitch weaves 19 formed by the chain stitch yarns 21 a and 21 b, and the insertion yarn 23 which is inserted into each course (actually into a loop-shaped portion r3 (a sinker loop) of the chain stitch weave 19) along the knitting direction C in the chain stitch weave 19.

As is clear from FIG. 1 and FIG. 3, as the chain stitch yarn 21, the first chain stitch yarn 21 a which is a thermal melting yarn, and the second chain stitch yarn 21 b having a higher melting temperature than the thermal melting yarn 21 a are fed from different beams B1 and B2 into individual reeds 64 a and 64 b, whereby the chain stitch weave 19 is knitted.

Further, the insertion yarn 23 is fed from a beam B4 to a reed for an insertion yarn 61 to be inserted into the chain stitch weave 19 which is formed by the first chain stitch yarn 21 a and the second chain stitch yarn 21 b.

As described previously, in the Raschel knitted fabric 20 according to the present invention, the chain stitch weave 19 is formed by the first and second chain stitch yarns 21 a and 21 b, the weft passage yarn 22 is knitted by transversely passing between the chain stitch weaves 19, and the insertion yarn 23 is inserted into each of the chain stitch weaves 19.

Here, the weft passage yarn 22 includes a net yarn which forms a base of the Raschel knitted fabric 20 and a pattern yarn, and the net yarn configures a basic net of the Raschel knitted fabric 20 together with the chain stitch yarn 21. On the other hand, the pattern yarn is a large number of yarns which are knitted in order to determine a lace pattern, and the lace pattern is determined according to the type of the yarn and a weft passage aspect.

That is, a large number of lattices are formed by each of the yarns 21 a, 21 b, 22, and 23, a through hole surrounded by each lattice is formed, and the lace pattern is determined by the shape of each lattice (the shape of the through hole) and the arrangement of the lattices. Further, in the Raschel knitted fabric 20, a portion in which the amount of yarn which is disposed per unit area is dense is referred to as a pattern portion, and a portion in which the amount of yarn which is disposed per unit area is sparse is referred to as a ground portion (including the basic net described above), and a pattern is also determined by the shapes and arrangement of the pattern portion and the ground portion.

2. Yarn Use

Chain Stitch Yarn

As the chain stitch yarn 21, the first chain stitch yarn 21 a and the second chain stitch yarn 21 b are used.

Therefore, each of the chain stitch weaves 19 is configured to be independently provided with two yarns (the first chain stitch yarn 21 a and the second chain stitch yarn 21 b).

As the first chain stitch yarn 21 a, for example, polyester-based polyurethane (trade name: Mobilon, manufactured by Nisshinbo Textile Inc.) is used. However, in this embodiment, the yarn 21 a has a relatively thin thickness in a range of 17 to 56 dtex. This yarn is a thermally weldable polyurethane yarn which is melted by heat treatment and welded to a yarn being in contact with the yarn, and at the same time, and is also a single fiber yarn (a filament yarn) made of a material having stretchability. In this yarn, it is practically impossible to hold the chain stitch weave 19 with this yarn alone and it is also difficult to perform chain stitch knitting with this yarn alone. In FIG. 1, it is drawn relatively thin for easy understanding. The melting temperature of the yarn 21 a is in a range of 150° C. to 180° C.

As the second chain stitch yarn 21 b, a long fiber yarn (a filament yarn) composed of a plurality of long fibers made of synthetic resin is used. For example, the second chain stitch yarn 21 b is made of polyamide (trade name: nylon), rayon, polyester, or the like, and the thickness thereof is in a range of about 33 to 56 dtex. The yarn 21 b is a yarn that forms the chain stitch weave 19 alone in a stretch Raschel lace of the related art. The melting temperature of the second chain stitch yarn 21 b is about 200° C.

As the weft passage yarn 22, a long fiber yarn (a filament yarn) composed of a plurality of long fibers made of synthetic resin is used. For example, the weft passage yarn 22 is made of polyamide (trade name: nylon), rayon, polyester, or the like, and the thickness thereof is in a range of about 33 to 78 dtex. The yarn 22 becomes a net yarn and a pattern yarn in the Raschel lace knitted fabric.

The melting temperature of the yarn 22 is also about 200° C.

As the insertion yarn 23, for example, polyester-based polyurethane is used. However, the yarn 23 has a thickness in a range of 156 to 310 dtex and is thicker than the first chain stitch yarn 21 a described above. In terms of the quality of a material, this yarn is the same type of material as the thermal melting yarn 21 a. However, since this yarn has a higher melting temperature and is thicker, the yarn remains even after the heat treatment step. Then, this yarn has strong stretchability, and therefore, after knitting, the yarn imparts stretchability to the Raschel knitted fabric 20. The melting temperature of the yarn 23 is about 210° C.

According to the study by the inventors, it has been clarified that by the heat treatment (described later), the thermal melting yarn 21 a is substantially melted and at least a part of the surface of the insertion yarn 23 is melted, so that a favorable welded state is obtained.

3. Raschel Knitting Machine

The Raschel knitted fabric 20 which is used in the present invention can be knitted by, for example, a back jacquard Raschel knitting machine. The back jacquard Raschel knitting machine 200 (hereinafter simply referred to as a knitted machine) has yarn guide means (specifically, reeds 61, 62, 63, 64 a, and 64 b) for guiding the chain stitch yarns 21 (21 a and 21 b), the weft passage yarns 22, and the insertion yarns 23 toward a knitting part 201 which is provided in the vicinity of the knitting needle 72.

In this embodiment, the reeds 64 a and 64 b for guiding the chain stitch yarns 21 toward the knitting part 201 are located further on the machine front side (the right side in FIG. 3, stated as a “machine front side” in the same drawing) than the other reeds 61, 62, and 63), and the reed 64 a is located further on the machine front side than the reed 64 b.

The reed 61 for guiding the insertion yarn 23 toward the knitting part 201 is disposed further on the knitting machine rear side (the left side in FIG. 3, stated as a “machine rear side” in the same drawing) than the reeds 62 and 63 for guiding the weft passage yarn 22 toward the knitting part 201. Here, the knitting machine rear side is the direction toward a hook portion from the back face of the knitting needle 72. However, the reed 62 for guiding the weft passage yarn 22 toward the knitting part 201 may be provided between the reeds 64 b and 63.

Specifically, as shown in FIGS. 3 and 4, the knitting machine 200 is realized by the reed for an insertion yarn 61, a jacquard bar 62 which is a jacquard reed, a large number of pattern reeds 63, and a pair of ground reeds 64 a and 64 b. The chain stitch yarns 21 a and 21 b are respectively threaded into the ground reeds 64 a and 64 b, and the weft passage yarn 22 is threaded into the jacquard bar 62 with respect to the net yarn and threaded into the pattern reed 63 with respect to the pattern yarn. The insertion yarn 23 is threaded into the reed for an insertion yarn 61.

The respective reeds 61 to 64 a and 64 b are radially arranged toward the knitting part 201 in which the knitting needle 72 catches the chain stitch yarn 21, and are disposed in the order of the ground reeds 64 a and 64 b, the plurality of pattern reeds 63, the jacquard bar 62, and the reed for an insertion yarn 61 as it goes toward the knitting machine rear side which is the direction in which the knitting needle 72 catches the chain stitch yarn 21. Therefore, the respective yarns are arranged in the order of the chain stitch yarns 21 (21 a and 21 b), the plurality of pattern yarns 22, the net yarn 22, and the insertion yarn 23 in the front-back direction of the knitting machine from a knitting position which is determined in advance. In this embodiment, the ground reed 64 a for the first chain stitch yarn 21 a is located on the front side with respect to the ground reed 64 b for the second chain stitch yarn 21 b, and the first chain stitch yarn 21 a is arranged in the front row of the knitting machine 200, and thus the handling of the first chain stitch yarn 21 a by a worker becomes easy.

A large number of knitting needles 72 are arranged in a direction (a front-to-back direction of the plane in FIGS. 3 and 4) orthogonal to the front-back direction of the knitting machine (the right-left direction in FIGS. 3 and 4), and fixed to a needle bar 69 serving as holding means for holding each knitting needle 72. The needle bar 69 moves each knitting needle 72 up and down. Further, the needle bar 69 is operated, so that each yarn which is guided by each of the reeds 61 to 64 a and 64 b is led to the knitting position which is determined in advance.

Each of the reeds 61 to 64 a and 64 b performs overlapping (stitch knitting motion) to move each of the corresponding yarns 23, 22, 21 a, and 21 b in the direction in which the knitting needles 72 are arranged, in a space on the knitting machine rear side with respect the knitting needle 72, in synchronism with the moving-up and -down motion of the knitting needle 72, and underlapping (insertion motion) to move each of the corresponding yarns 23, 22, 21 a, and 21 b in the direction in which the knitting needles 72 are arranged, in a space on the knitting machine front side with respect the knitting needle 72, in synchronism with the moving-up and -down motion of the knitting needle 72. Further, in addition to these lapping motions, a so-called swing (oscillating motion) in which the reed moves in the direction orthogonal to the direction in which the knitting needles 72 are arranged is performed. Specifically, there are two swing motions.

In a swing-in (back swing) motion which is the first swing motion, each of the corresponding yarns 23, 22, 21 a, and 21 b moves to pass the side of the knitting needle 72 from the space on the knitting machine rear side with respect the knitting needle 72 to the space on the knitting machine front side with respect the knitting needle 72. Further, in a swing-out (front swing) motion which is the second swing motion, each of the corresponding yarns moves to pass the side of the knitting needle 72 from the space on the knitting machine front side with respect the knitting needle 72 to the space on the knitting machine rear side with respect the knitting needle 72. A guide mounted on each of the reeds 61 to 64 a and 64 b operates, whereby each of the corresponding yarns passes around the knitting needle 72 along a path which is determined in advance, and thus the Raschel knitted fabric 20 which includes the corresponding respective yarns 23, 22, 21 a and 21 b is formed. The operating positional relationship of the chain stitch yarn 21 with respect to each knitting needle 72 is shown in FIG. 7A, and the operating positional relationship of the insertion yarn 23 with respect to each knitting needle 72 is shown in FIG. 7B.

Incidentally, with regard to the reeds 61 to 64 a and 64 b described above, the Raschel knitting machine 200 for knitting the Raschel knitted fabric 20 according to the present invention is provided with a first chain stitch yarn feeding amount adjustment mechanism TC1 which adjusts yarn feeding tension by adjusting the yarn feeding amount in a first chain stitch yarn feeding part b1 from the beam B1 for feeding the first chain stitch yarn 21 a to the ground reed 64 a (a first reed).

Further, the Raschel knitting machine 200 is also provided with a second chain stitch yarn feeding amount adjustment mechanism TC2 which adjusts yarn feeding tension by adjusting the yarn feeding amount in a second chain stitch yarn feeding part b2 from the beam B2 for feeding the second chain stitch yarn 21 b to the ground reed 64 b (a second reed).

Further, the knitting part 201 is provided with a stitch comb bar 71, a trick plate bar 68, and a tongue bar 70. A plurality of tongues corresponding to the respective knitting needles 72 are formed at a tip portion of the tongue bar 70. In the Raschel knitting machine 200, the Raschel knitted fabric 20 described above is knitted by the operations of the reeds 61 to 64 a and 64 b and the needle bar 69. Then, the knitted Raschel knitted fabric 20 is supplementarily knitted by the knitting assisting operation of the stitch comb bar 71 and passed through the trick plate bar 68, and the Raschel knitted fabric 20 is taken up by a take-up part provided in the vicinity of the knitting part 201.

FIGS. 5A to 5E are schematic sectional views for describing the movements of the knitting needle 72 and the ground reeds 64 a and 64 b in a chain stitch portion, and the knitting work of the chain stitch portion of the chain stitch yarns 21 a and 21 b proceeds in the order of FIG. 5A to FIG. 5E. In the knitting needle 72, a hook portion 50 for locking the chain stitch yarns 21 a and 21 b is formed at a tip portion, and a knitting needle stem 51 is formed at a base end portion. Further, a tongue 52 for opening and closing an opening which is formed by the hook portion 50 is formed at a tip portion of the tongue bar 70 shown in FIG. 4. The knitting needle 72 and the tongue 52 are formed so as to be individually movable up and down with respect to the ground reeds 64 a and 64 b. First, only the knitting of the chain stitch weave 19 will be described using FIGS. 5A to 5E, and the weft passage yarn 22 and the insertion yarn 23 which are knitted into the chain stitch weave 19 will be described later.

As shown in FIG. 5A, in a state where the ground reeds 64 a and 64 b are disposed in front of the knitting needle 72, the hook portion 50 hooks a new preceding loop-shaped portion r1 (a needle loop) which is formed by the chain stitch yarn 21, and the tongue 52 closes the opening of the hook portion 50. Next, as shown in FIG. 5B, the knitting needle 72 moves up toward the ground reeds 64 a and 64 b with respect to the tongue 52. In this way, the opening of the hook portion 50 is opened, and the preceding loop-shaped portion r1 of the chain stitch yarn 21 hooked by the hook portion 50 comes out from the hook portion 50 and moves to the knitting needle stem 51.

Next, as shown in FIG. 5C, the ground reeds 64 a and 64 b perform back swing with respect to the knitting needle 72. Next, the ground reeds 64 a and 64 b overlap, and the front swing is then performed, as shown in FIG. 5D. In this way, the chain stitch yarns 21 a and 21 b which are guided to the ground reeds 64 a and 64 b move so as to wind around the knitting needle 72, thereby forming a new loop-shaped portion r2 (a needle loop). The new loop-shaped portion r2 is hooked by the hook portion 50. Next, as shown in FIG. 5D, the tongue 52 moves up toward the hook portion 50 and closes the opening of the hook portion 50. At this time, the preceding loop-shaped portion r1 which is formed on the knitting needle stem 51 and the new loop-shaped portion r2 which the hook portion 50 locks are formed on the knitting needle 72.

Next, as shown in FIG. 5E, the knitting needle 72 and the tongue 52 move down together, whereby the preceding loop-shaped portion r1 comes out of the knitting needle 72 and moves toward a trick plate 53 side.

Then, in a state where the ground reeds 64 a and 64 b are disposed in front of the knitting needle 72, the hook portion 50 hooks the new loop-shaped portion r2 which is formed by the chain stitch yarns 21 a and 21 b, and thus substantially the same state as FIG. 5A is created. Then, by repeating the operation cycle shown using FIGS. 5A to 5E, the chain stitch weave 19 is sequentially formed in which the loop-shaped portions r1 and r2 are sequentially formed and a loop-shaped portion r3 (a sinker loop) connecting the loop-shaped portions r1 and r2 is sequentially formed.

In this example, the weft passage yarn 22 and the insertion yarn 23 are knitted into the chain stitch weave 19 while performing such work of knitting the chain stitch weave 19, whereby the Raschel knitted fabric 20 of this embodiment can be knitted.

FIGS. 6A to 6C are schematic sectional views for describing the movements of the jacquard bar 62 and the reed for an insertion yarn 61, and the operation proceeds in the order of FIG. 6A to FIG. 6C.

FIG. 6A, FIG. 6B, and FIG. 6C correspond to FIG. 5C, FIG. 5D, and FIG. 5E, respectively, and are drawings additionally showing the jacquard bar 62 and the reed for an insertion yarn 61. As described above, in the Raschel knitting machine 200, the jacquard bar 62 is disposed further on the knitting machine rear side than the ground reeds 64 a and 64 b that guide the chain stitch yarns 21. Further, the reed for an insertion yarn 61 is disposed further on the knitting machine rear side than the jacquard bar 62.

As shown in FIGS. 6A and 6B, in a state where the ground reeds 64 a and 64 b are disposed on the knitting machine rear side with respect to the knitting needle 72, the jacquard bar 62 and the reed for an insertion yarn 61 are also disposed on the knitting machine rear side with respect to the knitting needle 72. Further, as shown in FIG. 6B, in a state where the ground reeds 64 a and 64 b are disposed on the knitting machine front side with respect to the knitting needle 72, the jacquard bar 62 and the reed for an insertion yarn 61 are also disposed in front of the knitting needle 72.

In a state where the ground reeds 64 a and 64 b performs back swing, as shown in FIG. 6B, the jacquard bar 62 and the reed for an insertion yarn 61 perform underlapping, whereby the insertion yarn 23 and the weft passage yarn 22 which are guided straddle the chain stitch yarn 21. In this state, if a new course is formed by the chain stitch yarn 21, the insertion yarn 23 and the weft passage yarn 22 are knitted into the course. In this manner, the reed for an insertion yarn 61 and the jacquard bar 62 operate in synchronization with the swing motion of the ground reeds 64 a and 64 b.

In the Raschel knitting machine 200, the jacquard bar 62 is disposed further on the knitting machine front side than the reed for an insertion yarn 61. Accordingly, in a case where the insertion yarn 23 and the weft passage yarn 22 are knitted into the chain stitch portion which is formed by the ground reeds 64 a and 64 b, the insertion yarn 23 which is guided to the knitting position is located further on the knitting machine rear side than the weft passage yarn 22 which is guided to the knitting position, and the weft passage yarn 22 is located further on the knitted fabric front and back surface side of the Raschel knitted fabric 20 than the insertion yarn 23.

The above is the configuration of the facility for knitting the Raschel knitted fabric 20 according to the present invention and the knitting progress state.

Hereinafter, the manufacturing process for obtaining the Raschel lace knitted fabric will be described based on FIG. 8.

4. Manufacture of Raschel Lace Knitted Fabric

Knitting Step

First, the preparation of the knitting step s1 is performed. That is, the selection of each of the yarns 21 a, 21 b, 22, and 23 which are used for the knitting of the Raschel knitted fabric 20, the determination of a pattern to be formed in the Raschel knitted fabric 20, the design of a knitted fabric for forming a desired knitting weave, and the like are completed, whereby the preparation of the knitted fabric knitting is completed.

Then, threading is performed on the Raschel knitting machine 200 according to this design.

In the knitting step s1, the Raschel knitted fabric 20 having a large number of chain stitch weaves 19 shown in FIG. 1 in the knitted fabric weft direction W is knitted by knitting each of the yarns 21 a, 21 b, 22, and 23 such as the chain stitch yarns 21 a and 21 b and the insertion yarn 23 according to a knitting order designed in advance.

The Raschel knitted fabric 20 has a structure in which the chain stitch weave 19 is formed by both the first chain stitch yarn 21 a and the second chain stitch yarn 21 b and the insertion yarn 23 is inserted into the chain stitch weave 19. As described previously, as the insertion yarn 23, a relatively thick polyurethane yarn is inserted, and therefore, the knitted fabric 20 has stretchability. The Raschel knitting machine 200 performs knitting in a state where the insertion yarn 23 is stretched (a state where a certain degree of tension is applied thereto).

Further, as described previously, the first chain stitch yarn feeding amount adjustment mechanism TC1 which adjusts yarn feeding tension by adjusting the yarn feeding amount in the first chain stitch yarn feeding part b1 from the beam B1 for feeding the first chain stitch yarn 21 a to the ground reed 64 a (the first reed), and the second chain stitch yarn feeding amount adjustment mechanism TC2 which adjusts yarn feeding tension by adjusting the yarn feeding amount in the second chain stitch yarn feeding part b2 from the beam B2 for feeding the second chain stitch yarn 21 b to the ground reed 64 b (the second reed) are provided, whereby in the knitting, a good yarn feeding balance between the first chain stitch yarn 21 a and the second chain stitch yarn 21 b is taken.

The Raschel knitting machine 200 was set such that one rack is equal to 4800 rpm, and the yarn feeding amount of each yarn was set as follows.

First chain stitch yarn 21 a: 100 to 140 cm

Second chain stitch yarn 21 b: 100 to 140 cm

Weft passage yarn 22: 20 to 80 cm

Insertion yarn 23: 5 to 55 cm

In the Raschel knitted fabric 20 which is knitted in this way, each chain stitch weave 19 is knitted to be provided with two polyurethane yarns 21 a and 23.

Heat Treatment Step

In the heat treatment step s2, the Raschel knitted fabric 20 knitted in the knitting step s1 is heated to a temperature (for example, 200° C.) which is equal to or higher than the melting temperature of the first chain stitch yarn 21 a and equal to or lower than the melting temperatures of the other yarns 21 b, 22, and 23. That is, heat setting is performed, for example, for one minute at a temperature equal to or higher than the melting temperature (maximum 180° C.) of the first chain stitch yarn 21 a and equal to or lower than the melting temperatures (minimum 200° C.) of the second chain stitch yarn 21 b and the weft passage yarn 22. This heat treatment time is a time in which the first chain stitch yarn 21 a melts and exhibits weldability and each of the second chain stitch yarn 21 b, the weft passage yarn 22, and the insertion yarn 23 maintains the form of a yarn (remains as a yarn).

In this way, the first chain stitch yarn 21 a can be melted and welded to the yarn which is in contact with the first chain stitch yarn 21 a, while maintaining the pattern as a Raschel lace. In particular, the welding of the first chain stitch yarn 21 a and the insertion yarn 23 occurs favorably.

As a result, the first chain stitch yarn 21 a is welded to the insertion yarn 23 at a contact portion Y between at least the first chain stitch yarn 21 a and the insertion yarn 23, shown in FIG. 1. The first chain stitch yarn 21 a is partially welded to the other yarns 21 b and 22 as well. However, the portion Y is the strongest.

That is, the first chain stitch yarn 21 a and the insertion yarn 23 are different in melting temperature (here, a temperature at which the yarns completely melt). However, both the first chain stitch yarn 21 a and the insertion yarn 23 are made of polyester-based polyurethane, and therefore, they are strongly welded to each other. In contrast, since the second chain stitch yarn 21 b is made of polyamide and the weft passage yarn 22 is made of polyamide, rayon, or the like, the degree of welding is lower than in the first chain stitch yarn 21 a.

In heating the Raschel knitted fabric 20, the knitted fabric 20 is stretched, and thus the insertion yarn 23 maintains a state of being stretched to some extent (a tensioned state). Accordingly, as described previously, the welding between the polyurethane yarns is favorably generated and the Raschel lace knitted fabric subjected to this step retains stretchability due to shrinkage of the insertion yarn 23.

In this manner, the Raschel knitted fabric 20 is heated, whereby the contact portion Y between the first chain stitch yarn 21 a and the insertion yarn 23 is welded and the chain stitch yarns 21 are loosely welded to each other, whereby a Raschel lace knitted fabric is formed, and the process proceeds to the dyeing step s3.

Dyeing Step

In the dyeing step s3, the formed Raschel lace knitted fabric is scoured or dyed.

Resin Treatment and Drying Step

The resin treatment and drying step s4 is a step of applying a softener and can impart pliability to the Raschel lace knitted fabric.

After the resin treatment, the Raschel lace knitted fabric is dried with hot air of about 160° C. for 30 seconds.

Cutting and Sewing Step

In the cutting and sewing step s5, the knitted fabric is cut into a predetermined shape according to the use of the Raschel lace knitted fabric and sewn.

In the Raschel lace knitted fabric according to the present invention, since a fraying problem can be almost completely solved, a trouble caused by fraying does not occur at the time of the cutting and sewing.

According to the Raschel knitted fabric 20 of this embodiment as described above, the insertion yarn 23 having stretchability is knitted into the chain stitch weave 19, so that stretchability is provided to the chain stitch weave 19, and thus the Raschel lace knitted fabric having stretchability is realized. Further, a part of the contact portion Y between the first chain stitch yarn 21 a and the insertion yarn 23 is bonded. Accordingly, the positional deviation between the chain stitch weave 19 and the insertion yarn 23 and the positional deviation between the chain stitch yarns 21 a and 21 b are prevented, and thus distortion of the lattice is prevented. For example, even if an external force caused by a manufacturing step such as the sewing or the cutting of the Raschel lace knitted fabric, or an external force caused by a use state such as wearing or washing is applied, distortion of the lattice is prevented, and thus the shape of the lattice is maintained, a lace knitted fabric having good aesthetic appearance is obtained, and furthermore, the excellent aesthetic appearance can be maintained for a long period of time.

Furthermore, by utilizing the adhesiveness of the first chain stitch yarn 21 a which is knitted into the entire Raschel lace knitted fabric, the insertion yarn 23 is bonded and the chain stitch yarns 21 are also partially bonded together, and therefore, it is not a configuration in which partially different yarns are used, visual and tactile consistency is obtained, and aesthetic appearance and a feel are not impaired.

Another Embodiment

(1) In the embodiment described above, a case is shown where the first chain stitch yarn 21 a and the second chain stitch yarn 21 b are fed from different beams to the individual reeds 64 a and 64 b, one chain stitch weave 19 is knitted with these yarns 21 a and 21 b, and the insertion yarn 23 is inserted into the chain stitch weave 19.

A Raschel knitted fabric may be knitted with the chain stitch weave 19 in which instead of using two yarns 21 a and 21 b as described above, a thermally weldable conjugate yarn 210 is adopted as a chain stitch yarn and one chain stitch weave 19 is composed of a first chain stitch portion as a meltable yarn portion 210 a made of a meltable material, and a second chain stitch portion as a poorly-meltable yarn portion 210 b made of a poorly-meltable material.

An example of another embodiment is shown in FIG. 9.

The thermally weldable conjugate yarn is obtained by simultaneously spinning a plurality of (in the case shown in FIG. 9, two) different components and has a structure in which these components are stuck to each other continuously in a length direction. As this type of conjugate yarn, as the configuration thereof, a sheath-core type, a laminated type (a side-by-side type), or the like is known. However, in FIG. 9, a side-by-side type is shown.

In the present invention, since it is necessary to form a contact portion between the meltable yarn portion 210 a and the insertion yarn 23, the meltable yarn portion 210 a has a structure being exposed to the surface. For example, in a case where the conjugate yarn is of a sheath-core type, the sheath side is set to be the meltable yarn portion 210 a and the core side is set to be the poorly-meltable yarn portion 210 b. In the case of the laminated type, a part of at least the meltable yarn portion 210 a is set to be exposed on the yarn surface.

In the case of the present invention, it is possible to use a thermally weldable conjugate yarn using polyester-based polyurethane (having a melting temperature in a range of 150° C. to 180° C.) which is a meltable material, and nylon which is regarded as a poorly-meltable material.

In the case of this example, bonding of the poorly-meltable yarn portion 210 b and the insertion yarn 23 is realized according to the melting of the meltable yarn portion 210 a,

In another embodiment, a Raschel lace knitted fabric can be obtained by executing, in the heat treatment step, heat treatment to heat the Raschel knitted fabric obtained through the knitting step to a temperature equal to or lower than the melting temperatures of the poorly-meltable material and the weft passage yarn and equal to or higher than the melting temperature of the meltable material, in the knitted fabric tensioned state, for a treatment time in which the poorly-meltable yarn portion 210 b and the weft passage yarn 22 remain as yarns.

On the other hand, in the embodiment shown in FIG. 1, in one chain stitch weave 19 shown in the same drawing, a first chain stitch portion is formed by the first chain stitch yarn 21 a and a second chain stitch portion is formed by the second chain stitch yarn 21 b.

(2) In the embodiment described above, as the first chain stitch yarn 21 a, a yarn having a thickness in a range of 17 to 56 dtex is used. However, according to the study by the inventors, it was also possible to adopt a yarn having a thickness thinner than the thickness of the insertion yarn 23, specifically, a yarn having a thickness of 156 dtex.

Further, as the second chain stitch yarn 21 b, in a case of using nylon or polyester, a yarn having a thickness of 33, 40, 44, 56, or 78 dtex can be adopted.

On the other hand, as the weft passage yarn 22, in a case of using nylon or polyester, a yarn having a thickness of 33, 40, 44, 56, or 78 dtex can be adopted.

The heat treatment temperature in the heat treatment step s2 is set to be equal to or higher than the melting temperature of the first chain stitch yarn 21 a which is specifically used, and equal to or lower than the temperature on the low temperature side out of the melting temperatures of the second chain stitch yarn 21 b and the weft passage yarn 22, and it is possible to perform treatment only for a time in which the second chain stitch yarn 21 b and the weft passage yarn 22 remain as yarns in this heat treatment.

Specifically, in a case where the melting temperature of the first chain stitch yarn 21 a is in a range of 150° C. to 180° C. and the melting temperatures of the second chain stitch yarn 21 b and the weft passage yarn 22 is 200° C., the heat treatment temperature can be set to be 180° C. or more and 200° C. or less (preferably 190° C. or more and 200° C. or less). The heat treatment time is set to be in a range of about 30 to 90 seconds. Since this treatment time is very short, the second chain stitch yarn 21 b, the weft passage yarn 22, and the insertion yarn 23 remain as yarns.

(3) In the embodiment described above, an example of the knitting in which the first chain stitch yarn 21 a, the second chain stitch yarn 21 b, and the insertion yarn 23 are provided on the entire Raschel knitted fabric 20 is shown. However, the key of the present invention is to weld the first chain stitch portion (for example, the first chain stitch yarn 21 a) made of the thermally meltable material to the insertion yarn 23, and therefore, the first chain stitch portion, the second chain stitch portion, and the insertion yarn 23 may be knitted into only a part of the chain stitch weave 19 according to the purpose of use of the Raschel lace knitted fabric associated with the cutting thereof (according to a cutting location).

(4) In the embodiment described above, as the insertion yarn 23, a polyurethane yarn is inserted as a yarn for imparting stretchability to the Raschel lace knitted fabric. In addition to this yarn 23, a yarn different from the insertion yarn 23 may be inserted into the chain stitch weave 19 which is obtained by knitting, as a floating insertion yarn in a knitted form in which a part of the yarn floats on the back surface of the Raschel knitted fabric.

As such a floating insertion yarn, if a cotton yarn, a rayon yarn, a multifilament yarn, or the like is selected, especially, a good feel can be obtained.

(5) In the embodiment described above, knitting in which in the related art, for prevention of fraying, the chain stitch yarn 21 which is referred to as “warp traverse” and has formed the chain stitch weave 19 at a predetermined position in the knitted fabric weft direction W crosses over to a wale adjacent thereto, forms the chain stitch weave 19 over several courses at that position, and then returns to the original wale to further form the chain stitch weave 19 has not been particularly described.

In the Raschel lace knitted fabric according to the present invention, fraying is effectively prevented, and therefore, the “warp traverse” is not needed virtually. Alternatively, even if it is provided, the number thereof in the knitting direction C can be remarkably reduced. As a result, the “warp traverse” parts which have been provided relatively frequently in the related art are remarkably reduced from a Raschel lace knitted fabric (the “warp traverse” which has been provided in a unit in a range of several courses to several tens of courses in the related art is provided in a unit of several hundred courses or is not provided at all), and therefore, it is possible to exhibit a beautiful aesthetic appearance without making steps frequently appear in the Raschel knitted fabric (in particular, the net composed of the chain stitch weave 19 and the net yarn 22).

(6) In the embodiment described above, with respect to the insertion of the insertion yarn 23, as shown in FIGS. 1 and 9, an example of so-called forward hooking in which the insertion yarn 23 is inserted into the sinker loop toward the outside from the inside of the chain stitch in the knitting direction C is shown. However, so-called backward hooking in which the insertion yarn 23 is inserted into the sinker loop toward the inside from the outside of the chain stitch can also be adopted. 

What is claimed is:
 1. A method of manufacturing a Raschel lace knitted fabric, which obtains the Raschel lace knitted fabric by executing the following steps: a knitting step of knitting a Raschel knitted fabric by feeding a plurality of chain stitch yarns each forming a chain stitch weave extending in a knitting direction, a weft passage yarn which is knitted in a knitted fabric weft direction between a plurality of chain stitch weaves formed by the chain stitch yarns, and a thermal melting yarn exhibiting weldability by being partially or entirely melted by being heated, to a Raschel knitting machine, and a heat treatment step of heat-treating the Raschel knitted fabric which is obtained through the knitting step, wherein in the knitting step, a plurality of chain stitch weaves are knitted in which a meltable yarn portion made of thermally weldable polyurethane which is a meltable material which is partially or entirely melted by being heated is set to be a first chain stitch portion, a poorly-meltable yarn portion made of a poorly-meltable material having a higher melting temperature than the meltable material is set to be a second chain stitch portion, the first chain stitch portion and the second chain stitch portion are provided in the same chain stitch weave, and a surface of the first chain stitch portion is in an exposed state, and a Raschel knitted fabric is knitted in which the weft passage yarn is set to be a poorly-meltable yarn made of a poorly-meltable material having a higher melting temperature than the meltable material, and an insertion yarn made of a polyurethane material is inserted into the chain stitch weave, and wherein in the heat treatment step, heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than melting temperatures of the poorly-meltable material and the weft passage yarn and equal to or higher than a melting temperature of the meltable material in a knitted fabric tensioned state where a contact portion between the first chain stitch portion and the insertion yarn is formed is executed for a treatment time in which each of the poorly-meltable yarn portion, the weft passage yarn, and the insertion yarn remains as a yarn, so that a Raschel lace knitted fabric in which the insertion yarn is welded to the chain stitch weave is obtained.
 2. The method of manufacturing a Raschel lace knitted fabric according to claim 1, wherein a first chain stitch yarn which is made of the meltable material and is a filament yarn and a second chain stitch yarn made of the poorly-meltable material are fed from different beams to individual reeds, and the first chain stitch portion and the second chain stitch portion are knitted in the same chain stitch weave by the first chain stitch yarn and the second chain stitch yarn, respectively, and the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch yarn and the second chain stitch yarn, so that a Raschel knitted fabric is knitted, and wherein in the heat treatment step, heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than the melting temperatures of the second chain stitch yarn and the weft passage yarn and equal to or higher than the melting temperature of the first chain stitch yarn is executed for a treatment time in which each of the second chain stitch yarn, the weft passage yarn, and the insertion yarn remains as a yarn, thereby obtaining a Raschel lace knitted fabric.
 3. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein the first chain stitch yarn is a yarn that is thinner than the insertion yarn, a surface of the insertion yarn is melted in the heat treatment in the heat treatment step, and the first chain stitch yarn is welded to the surface of the insertion yarn.
 4. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein the first chain stitch yarn is thinner than the insertion yarn.
 5. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine.
 6. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein the second chain stitch yarn is a nylon yarn.
 7. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.
 8. The method of manufacturing a Raschel lace knitted fabric according to claim 2, wherein the first chain stitch yarn is a thermally weldable polyurethane yarn having a thickness in a range of 17 to 156 dtex and a melting temperature in a range of 150° C. to 180° C., the second chain stitch yarn is a nylon yarn having a thickness in a range of 33 to 78 dtex and a melting temperature of 200° C., the insertion yarn is a polyurethane yarn having a thickness in a range of 156 to 310 dtex and a melting temperature in a range of 190° C. to 220° C., and in the heat treatment step, the Raschel knitted fabric obtained through the knitting step is heat-treated for a time in a range of 30 to 90 seconds at a temperature within a heating temperature range of 190° C. or more and 200° C. or less.
 9. The method of manufacturing a Raschel lace knitted fabric according to claim 1, wherein in the knitting step, a conjugate yarn having the meltable yarn portion and the poorly-meltable yarn portion in a single yarn is fed to a single reed to be knitted into a chain stitch weave having the first chain stitch portion and the second chain stitch portion, and the insertion yarn is inserted into the chain stitch weave, thereby knitting the Raschel knitted fabric.
 10. The method of manufacturing a Raschel lace knitted fabric according to claim 1, wherein in the knitting step, a chain stitch weave having the first chain stitch portion, the second chain stitch portion, and the insertion yarn is knitted on the entire Raschel knitted fabric.
 11. The method of manufacturing a Raschel lace knitted fabric according to claim 1, wherein in the knitting step, a yarn different from the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch portion and the second chain stitch portion, as a floating insertion yarn in a knitted form in which a part of the yarn floats on a back surface of the Raschel knitted fabric.
 12. The method of manufacturing a Raschel lace knitted fabric according to claim 3, wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine.
 13. The method of manufacturing a Raschel lace knitted fabric according to claim 4, wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine.
 14. The method of manufacturing a Raschel lace knitted fabric according to claim 3, wherein the second chain stitch yarn is a nylon yarn.
 15. The method of manufacturing a Raschel lace knitted fabric according to claim 4, wherein the second chain stitch yarn is a nylon yarn.
 16. The method of manufacturing a Raschel lace knitted fabric according to claim 5, wherein the second chain stitch yarn is a nylon yarn.
 17. The method of manufacturing a Raschel lace knitted fabric according to claim 3, wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.
 18. The method of manufacturing a Raschel lace knitted fabric according to claim 4, wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.
 19. The method of manufacturing a Raschel lace knitted fabric according to claim 5, wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.
 20. The method of manufacturing a Raschel lace knitted fabric according to claim 6, wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided. 